Recently, interest in carbon nanostructures, such as carbon nanotubes, has increased in order to develop new chemical and biological sensors that utilize the sensitivity of the carbon nanotube to its surrounding environment. Some sensor strictures can be based on the various types of carbon nanotubes.
In one example, a conventional sensor based on the carbon nanotube can have multiple carbon nanotubes and square-shaped electrodes disposed at end portions of the carbon nanotubes. In accordance with the conventional sensor, when a reference voltage is applied to a second electrode, the carbon nanotube resistance can vary according to an object to be sensed, and a voltage or a current of a first electrode can vary according to the variation of the resistance of the carbon nanotube.